HM 10 BLE Question

Hi Guys,
I've got two UART HM-10 BLE devices one order, I was going to connect each two to an arduino UNO dev kit, one is standalone taking temperature readings etc. and the other is connected to a PC via the UNOs USB-Serial. One of the things I was interested in doing was configuring the remote HM-10 BLE device with AT commands from the PC side through a terminal.

I know you cant do this when devices are in connected mode or can you?

If I need two way comms, then I need to connect/pair both devices rather than reading a BLE nodes data like temperature etc. using GATT

To address this: I was thinking of an algorithm where I sent a string while connected to the remote BLE device,
The string for example "AAAAA9600" would be read by the arduino.
This string might be for changing the baud rate to 9600 etc.
it would disconnect the BLE device and run the AT command. The BREAK I/O on the device has got a pull-up attached to it and a BC547 transistor would be used to pull BREAK low to disconnect again.

My question is how would I auto reconnect and if I eventually had an APP on Android how long would it take to reconnect, I know BLE is significantly faster at connecting than classic Bluetooth.
Or is there a better way of doing it, I could use an FTDI serial cable on the remote device and connect it to a terminal and configure it that way, I was just thinking it would be neat to remotely configure AT commands and see the responses.

Any help would be greatly appreciated. Thanks guys

cfcorp:
I know you cant do this when devices are in connected mode or can you?

You are correct, you can't.

If I need two way comms, then I need to connect/pair both devices rather than reading a BLE nodes data like temperature etc. using GATT

To address this: I was thinking of an algorithm where I sent a string while connected to the remote BLE device,
The string for example "AAAAA9600" would be read by the arduino.
This string might be for changing the baud rate to 9600 etc.
it would disconnect the BLE device and run the AT command. The BREAK I/O on the device has got a pull-up attached to it and a BC547 transistor would be used to pull BREAK low to disconnect again.

My question is how would I auto reconnect and if I eventually had an APP on Android how long would it take to reconnect, I know BLE is significantly faster at connecting than classic Bluetooth.

I believe it is practical to send a formatted command via bluetooth which includes a signal to disconnect and then restore the power to Bluetooth, thereby putting it AT mode. The rest of that command configures bluetooth and makes the connection. It would probably need to be a slave so that it won't autoconnect, and I guess there would have to be some control over the master too, in order to avoid embarrassment, like go off-air for a couple of seconds.

, I was just thinking it would be neat to remotely configure AT commands and see the responses.

"Neat" is a relative term that may quickly tarnish. There are surely other tasks that would better justify the effort of all this.

Using Mode2 you can send AT commands wirelessly to the remote HM-10.
There are AT commands to read and write the HM-10 programmable pins.
If you use a DS18B20 or a DHT11 you can have the temperature value automatically placed in the advertising data (along with battery and humidity).

See HM-10 Bluetooth 4 BLE Modules